Math Problem Statement
An architect is allowed 15 square yards of floor space to add a small bedroom to a house. Because of the room's design in relationship to the existing structure, the width of the rectangular floor must be 7 yards less than two times the length. Find the length and width of the rectangular floor that the architect is permitted.
Solution
We are tasked with finding the length and width of the rectangular floor. The total floor area is given as 15 square yards, and the width of the rectangular floor is defined as 7 yards less than twice the length.
Let's define the length and width in terms of a variable:
- Let the length of the floor be yards.
- The width of the floor is yards (because it's 7 yards less than twice the length).
The area of a rectangle is given by the formula: Substituting the given area and the expression for the width: Now let's solve this equation:
Step 1: Expand the equation
Step 2: Rearrange the equation into standard quadratic form
Step 3: Solve the quadratic equation
We can solve this using the quadratic formula, where , , and : Substitute the values of , , and : This gives two possible solutions for : or Since length must be positive, we discard . Therefore, the length is yards.
Step 4: Find the width
Substitute into the expression for the width:
Final Answer:
- The length of the rectangular floor is yards.
- The width of the rectangular floor is yards.
Would you like further clarification or details?
Here are 5 related questions for deeper understanding:
- How do you derive the quadratic formula used to solve for ?
- Why is the negative solution for discarded in this context?
- What other real-life applications might require solving similar quadratic equations?
- How would the solution change if the total area allowed was different, say 20 square yards?
- Can you confirm the solution by re-checking the area with the calculated length and width?
Tip: When solving quadratic equations, always check whether both solutions are valid within the problem’s context.
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Math Problem Analysis
Mathematical Concepts
Algebra
Quadratic Equations
Area of a Rectangle
Formulas
Area of rectangle = length × width
Quadratic equation formula ax^2 + bx + c = 0
Theorems
Quadratic Formula
Suitable Grade Level
Grades 9-10